[Federal Register Volume 87, Number 55 (Tuesday, March 22, 2022)]
[Proposed Rules]
[Pages 16123-16126]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-05668]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-0284; Project Identifier MCAI-2021-01369-A]
RIN 2120-AA64


Airworthiness Directives; Viking Air Limited (Type Certificate 
Previously Held by Bombardier Inc. and de Havilland, Inc.) Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain Viking Air Limited (type certificate previously held by 
Bombardier Inc. and de Havilland, Inc.) Model DHC-6-1, DHC-6-100, DHC-
6-200, DHC-6-300, and DHC-6-400 airplanes. This proposed AD results 
from mandatory continuing airworthiness information (MCAI) originated 
by an aviation authority of another country to identify and correct an 
unsafe condition on an aviation product. The MCAI identifies the unsafe 
condition as binding of the rod end bearing connecting the lower fuel 
control unit (FCU) push rod assembly to the FCU power lever. This 
proposed AD would require performing tests, inspections, and 
lubrication of the FCU push rod assemblies, and replacing them with 
improved parts as necessary. The FAA is proposing this AD to address 
the unsafe condition on these products.

DATES: The FAA must receive comments on this proposed AD by May 6, 
2022.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: (202) 493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE, Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this NPRM, contact Viking Air 
Ltd., 1959 de Havilland Way, Sidney British Columbia, Canada V8L 5V5; 
phone: (800) 663-8444; email: [email protected]; 
website: https://www.vikingair.com. You may view this service 
information at the FAA, Airworthiness Products Section, Operational 
Safety Branch, 901 Locust, Kansas City, MO 64106. For information on 
the availability of this material at the FAA, call (817) 222-5110.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2022-0284; or in person at 
Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal holidays. The AD docket contains this NPRM, the MCAI, 
any comments received, and other information. The street address for 
Docket Operations is listed above.

FOR FURTHER INFORMATION CONTACT: Elizabeth Dowling, Aviation Safety 
Engineer, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590; phone: (516) 228-7300; email: 
[email protected].

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA invites you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2022-0284; 
Project Identifier MCAI-2021-01369-A'' at the beginning of your 
comments. The most helpful comments reference a specific portion of the 
proposal, explain the reason for any recommended change, and include 
supporting data. The FAA will consider all comments received by the 
closing date and may amend this proposal because of those comments.
    Except for Confidential Business Information (CBI) as described in 
the following paragraph, and other information as described in 14 CFR 
11.35, the FAA will post all comments received, without change, to 
https://www.regulations.gov, including any personal information you 
provide. The agency will also post a report summarizing each 
substantive verbal contact received about this NPRM.

Confidential Business Information

    CBI is commercial or financial information that is both customarily 
and actually treated as private by its owner. Under the Freedom of 
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public 
disclosure. If your comments responsive to this NPRM contain commercial 
or financial information that is customarily treated as private, that 
you actually treat as private, and that is relevant or responsive to 
this NPRM, it is important that you clearly designate the submitted 
comments as CBI. Please mark each page of your submission containing 
CBI as ``PROPIN.'' The FAA will treat such marked submissions as 
confidential under the FOIA, and they will not be placed in the public 
docket of this NPRM. Submissions containing CBI should be sent to 
Elizabeth Dowling, Aviation Safety Engineer, New York ACO Branch, FAA, 
1600 Stewart Avenue, Suite 410, Westbury, NY 11590. Any commentary that 
the FAA receives which is not specifically designated as CBI will be 
placed in the public docket for this rulemaking.

Background

    Transport Canada, which is the aviation authority for Canada, has 
issued Transport Canada AD CF-2021-42, dated November 26, 2021 
(referred to after this as ``the MCAI''), to address an unsafe 
condition on certain serial-numbered Viking Air Limited Model DHC-6 
series 1, DHC-6 series 100, DHC-6 series 110, DHC-6 series 200, DHC-6 
series 210, DHC-6 series 300, DHC-6 series 310, DHC-6 series 320, and 
DHC-6 series 400 airplanes with certain part-numbered FCU push rod 
assemblies installed. The MCAI states:

    There have been in-service reports of binding of [part number] 
P/N VSC30-3A rod end bearings used in the linkage for the lower FCU 
push rod assembly P/N C6CE1398-7. The lower FCU push rod assembly is 
connected to the FCU power lever and contains a rod end bearing at 
each end. P/N VSC30-3A rod end bearings, fabricated with a metal 
inner race and a dry film lubricant, have been incorporated on FCU 
push rod assemblies introduced through Viking Air Ltd (Viking) MOD 
6/2347. P/N VSC30-3A rod end bearings may have also been installed 
in-service as a replacement part in lower FCU push rod assembly P/N 
C6CE1398-3. In one instance, binding of the lower FCU push rod 
bearing resulted in one engine failing to return to a lower power 
setting from a higher power setting when

[[Page 16124]]

commanded, which subsequently resulted in the need to perform an in-
flight engine shutdown during final approach. An investigation also 
revealed that binding of P/N VSC30-3A rod end bearings can occur 
after a period of non-utilization of the aeroplane.
    This condition, if not detected and corrected, may lead to the 
inability to reduce power on the affected engine, resulting in the 
need to perform an in-flight engine shutdown, and consequently 
leading to reduced control of the aeroplane and increased pilot 
workload during this critical phase of flight.
    To address this unsafe condition, this [Transport Canada] AD 
mandates initial and repetitive functional checks, special detailed 
inspection (SDI) and lubrication of the affected FCU push rod 
assembly, and its replacement, as required, with a redesigned FCU 
push rod assembly with improved reliability (MOD 6/2484), in 
accordance with Viking Service Bulletin (SB) V6/0063. This 
[Transport Canada] AD also prohibits the installation of an affected 
FCU push rod assembly as a replacement part on applicable 
aeroplanes.

    You may examine the MCAI in the AD docket at https://www.regulations.gov by searching for and locating Docket No. FAA-2022-
0284.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed the following:
     Viking DHC-6 Twin Otter Service Bulletin (SB) No. V6/0063, 
Revision A, dated February 1, 2021 (Viking SB V6/0063, Revision A), 
which specifies procedures for performing tests, inspections, and 
lubrication of the FCU push rod assemblies; and
     Viking DHC-6 Twin Otter Technical Bulletin No. V6/00155, 
Revision NC, dated September 14, 2020, which specifies procedures for 
replacing the FCU push rod assemblies with improved parts.
    This service information is reasonably available because the 
interested parties have access to it through their normal course of 
business or by the means identified in the ADDRESSES section.

Other Related Service Information

    The FAA also reviewed Viking DHC-6 Twin Otter SB No. V6/0063, 
Revision NC, dated June 7, 2019 (Viking SB V6/0063, Revision NC), which 
specifies procedures for performing tests, inspections, and lubrication 
of the FCU push rod assemblies. Viking revised this service information 
and issued Viking SB V6/0063 Revision A to extend the lubrication 
requirement of Mod 6/2347 rod ends to all operating environments, add 
repeat inspections, and introduce a test and lubrication for airplanes 
that have not been in operation after a period of time before re-entry 
into service.

FAA's Determination

    This product has been approved by the aviation authority of another 
country, and is approved for operation in the United States. Pursuant 
to the FAA's bilateral agreement with this State of Design Authority, 
it has notified the FAA of the unsafe condition described in the MCAI 
and service information referenced above. The FAA is issuing this NPRM 
after determining the unsafe condition described previously is likely 
to exist or develop in other products of the same type design.

Proposed AD Requirements in This NPRM

    This proposed AD would require accomplishing the actions specified 
in the service information described previously.

Differences Between This Proposed AD and the MCAI

    The MCAI applies to Viking Air Limited Model DHC-6 series 110, DHC-
6 series 210, DHC-6 series 310, and DHC-6 series 320, and this proposed 
AD would not because these models do not have an FAA type certificate. 
Transport Canada Model DHC-6 series 1, DHC-6 series 100, DHC-6 series 
200, DHC-6 series 300, and DHC-6 series 400 airplanes correspond to FAA 
Model DHC-6-1, DHC-6-100, DHC-6-200, DHC-6-300, and DHC-6-400 
airplanes, respectively.
    The MCAI requires reporting information to the manufacturer, and 
this proposed AD would not.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 34 airplanes of U.S. registry. The FAA estimates the following 
costs to comply with this proposed AD:

                                                 Estimated Costs
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                                                                                                 Cost on U.S.
              Action                    Labor cost        Parts cost     Cost per airplane        operators
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Test, inspect, and lubricate the   1 work-hour x $85               N/A  $85 per inspection   $2,890 per
 FCU push rod assemblies.           per hour = $85.                      cycle.               inspection cycle.
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    The FAA estimates the following costs to replace the FCU push rod 
assemblies. The agency has no way of determining the number of 
airplanes that might need these replacements:

                                               On-Condition Costs
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                                                                                                     Cost per
                    Action                                Labor cost               Parts cost        airplane
----------------------------------------------------------------------------------------------------------------
Replace both FCU push rod assemblies.........  3 work-hours x $85 per hour =               $60             $315
                                                $255.
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Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. Subtitle VII: Aviation Programs 
describes in more detail the scope of the Agency's authority.
    The FAA is issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701: General requirements. 
Under that section, Congress charges the FAA with promoting safe flight 
of civil aircraft in air commerce by prescribing regulations for 
practices, methods, and procedures the Administrator finds necessary 
for safety in air commerce. This regulation is within the scope of

[[Page 16125]]

that authority because it addresses an unsafe condition that is likely 
to exist or develop on products identified in this rulemaking action.

Regulatory Findings

    The FAA determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would not 
have a substantial direct effect on the States, on the relationship 
between the national Government and the States, or on the distribution 
of power and responsibilities among the various levels of government.
    For the reasons discussed above, I certify this proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Will not affect intrastate aviation in Alaska, and
    (3) Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

    Authority:  49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13   [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive:

Viking Air Limited (Type Certificate Previously Held by Bombardier 
Inc. and de Havilland, Inc.): Docket No. FAA-2022-0284; Project 
Identifier MCAI-2021-01369-A.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by May 6, 2022.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Viking Air Limited (Type Certificate 
Previously Held by Bombardier Inc. and de Havilland, Inc.) Model 
DHC-6-1, DHC-6-100, DHC-6-200, DHC-6-300, and DHC-6-400 airplanes, 
serial numbers 001 through 989, certificated in any category.

(d) Subject

    Joint Aircraft System Component (JASC) Code 7600, Engine 
Controls.

(e) Unsafe Condition

    This AD was prompted by mandatory continuing airworthiness 
information (MCAI) originated by an aviation authority of another 
country to identify and correct an unsafe condition on an aviation 
product. The MCAI identifies the unsafe condition as binding of the 
rod end bearing connecting the lower fuel control unit (FCU) push 
rod assembly to the FCU power lever. The unsafe condition, if not 
addressed, could lead to the inability to reduce power on the 
affected engine, which could result in an in-flight engine shutdown 
and reduced airplane control.

(f) Definitions

    (1) For purposes of this AD, an ``affected FCU pushrod 
assembly'' is one of the following:
    (i) Lower FCU push rod assembly part number (P/N) C6CE1398-7; or
    (ii) Lower FCU push rod assembly P/N C6CE1398-3 with P/N VSC30-
3A rod end bearing installed.
    Note 1 to paragraph (f)(1): P/N C6CE1398-7 may also be referred 
to as modification (MOD) 6/2347.
    (2) For purposes of this AD, a ``serviceable FCU push rod 
assembly'' is lower FCU push rod assembly P/N C6CE1398-9.
    Note 2 to paragraph (f)(2): P/N C6CE1398-9 may also be referred 
to as MOD 6/2484.

(g) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(h) Required Actions

    (1) Within 125 hours time-in-service (TIS) after the effective 
date of this AD or within 30 days after the effective date of this 
AD, whichever occurs first, test each affected FCU push rod assembly 
for binding and restriction in accordance with the Accomplishment 
Instructions, paragraphs A.1. through A.3., in Viking DHC-6 Twin 
Otter Service Bulletin No. V6/0063, Revision A, dated February 1, 
2021 (Viking SB V6/0063, Revision A).
    (i) If there is any binding or restriction, before further 
flight, remove both affected FCU push rod assemblies from service 
and install serviceable FCU push rod assemblies in accordance with 
the Accomplishment Instructions, paragraph A.4., in Viking SB V6/
0063, Revision A, and the Accomplishment Instructions, Sections A 
through C, in Viking DHC-6 Twin Otter Technical Bulletin No. TB V6/
00155, Revision NC, dated September 14, 2020 (Viking TB V6/00155, 
Revision NC).
    (ii) If there is no binding and no restriction, before further 
flight, remove each affected FCU push rod assembly, clean the push 
rod ends, and inspect each affected FCU push rod assembly for 
corrosion and condition of the lubricant. Pay particular attention 
to the bearing ball and race.
    (A) If there is no corrosion and the lubricant color and texture 
is normal, before further flight, lubricate each affected FCU push 
rod assembly in accordance with the Accomplishment Instructions, 
Section C, in Viking SB V6/0063, Revision A.
    (B) If there is corrosion or if the lubricant is abnormal in 
color (too dark) or texture (too sticky), before further flight, 
remove both affected FCU push rod assemblies from service and 
install serviceable FCU push rod assemblies in accordance with the 
Accomplishment Instructions, paragraph A.4, in Viking SB V6/0063, 
Revision A and the Accomplishment Instructions, Sections A through 
C, in Viking TB V6/00155, Revision NC.
    (2) Repeat the requirements of this AD as follows until both 
affected FCU push rod assemblies are replaced.
    (i) Test and lubrication: At intervals not to exceed 125 hours 
TIS or before further flight anytime the airplane has not been 
operated for a period of 30 days, whichever occurs first.
    (ii) Inspection: At intervals not to exceed 1,500 hours TIS.
    (3) As of the effective date of this AD, do not install an 
affected FCU push rod assembly on any airplane.

(i) Credit for Previous Actions

    You may take credit for the test, inspection, replacement, and 
lubrication required by paragraphs (h)(1) and (2) of this AD if you 
performed those actions before the effective date of this AD using 
Viking DHC-6 Twin Otter Service Bulletin No. V6/0063, Revision NC, 
dated June 7, 2019.

(j) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, New York ACO Branch, FAA, has the authority to 
approve AMOCs for this AD, if requested using the procedures found 
in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request 
to your principal inspector or local Flight Standards District 
Office, as appropriate. If sending information directly to the 
manager of the certification office, send it to the attention of the 
person identified in paragraph (k)(1) of this AD.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

(k) Related Information

    (1) For more information about this AD, contact Elizabeth 
Dowling, Aviation Safety Engineer, New York ACO Branch, FAA, 1600 
Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (516) 228-
7300; email: [email protected].
    (2) Refer to Transport Canada AD CF-2021-42, dated November 26, 
2021, for more information. You may examine the Transport Canada AD 
in the AD docket at https://www.regulations.gov by searching for and 
locating it in Docket No. FAA-2022-0284.
    (3) For service information identified in this AD, contact 
Viking Air Ltd., 1959 de Havilland Way, Sidney British Columbia, 
Canada V8L 5V5; phone: (800) 663-8444; email: 
[email protected]; website: https://www.vikingair.com. You may review this referenced service 
information at the FAA, Airworthiness Products Section, Operational

[[Page 16126]]

Safety Branch, 901 Locust, Kansas City, MO 64106. For information on 
the availability of this material at the FAA, call (817) 222-5110.

    Issued on March 11, 2022.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2022-05668 Filed 3-21-22; 8:45 am]
BILLING CODE 4910-13-P